increasing float speed does nothing

hi i’m trying to increase the speed of my character controller but i can’t seem to figure out how. changing the public float speed from 12 to 100 does nothing

here’s what i have so far, any help would be much appreciated

public class MoveCharacter2 : MonoBehaviour

{
    public CharacterController controller;
    public float speed = 20f;

    // Update is called once per frame

    void Update()

    {
        float z = Input.GetAxis("Vertical");

        Vector3 move = Quaternion.Euler(0, Camera.main.transform.eulerAngles.y, 0) * new Vector3(0f, 0f, z * speed * Time.deltaTime);

        controller.Move(move * speed * Time.deltaTime);

    }

}

You are multiplying with speed * Time.deltaTime too many times, the value will probably be very small. Try

Vector3 move = Quaternion.Euler(0, Camera.main.transform.eulerAngles.y, 0) * new Vector3(0f, 0f, z);
controller.Move(move * speed * Time.deltaTime);